Fingerprints are inherent and unique features of the human body. A fingerprint is composed of a series of ridges and valleys on the surface of the skin. Details of the ridges and valleys usually include bifurcation of the ridge, an end of the ridge, arch, tented arch, left-handed, right-handed, spiral, or double spiral, which determine the uniqueness of the fingerprint pattern. Fingerprint identification devices developed based on the above details are used for personal authentication, and are widely used in devices such as photosensitive fingerprint identification devices and capacitive fingerprint identification devices.
When one capacitive fingerprint identification device is used to identify a fingerprint, if a distance between a finger and the capacitive fingerprint identification device is greater than 300 um, a capacitance signal will be too small to be read out. Thus, the capacitive fingerprint identification device is usually used only in a non-displaying area. For example, the capacitive fingerprint identification device may be applied to a Home button of a mobile phone, and may identify a fingerprint by means of sliding or pressing the Home button. In other words, the current fingerprint identification devices are used only at special positions such as buttons to identify fingerprints and cannot be disposed in a display area and thus, full-screen fingerprint identification cannot be achieved on display apparatuses.